Island



-' (No Model.)

0 D. ROGERS. WOOD SGREW.

; 3,9 I Patented 001:. 29, 1889..

WlTNESSEE. I INVENTOR- UNITED I STATES PATENT OFFICE.

CHARLES 1). ROGERS, or PRov IDENo-E, RHODE ISLAND, ASSIGNOR o THE AMERICAN scRE coMrANY, or SAME PLACE.

WOOD-SCREW.

' SPECIFICATION forming part of Letters Patent No. 413,968, dated October 29, 1889.

tion, such as will enable others skilled inthe- TO art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of ref-- erence marked thereon, which form'a part of this specification.

I 5 Heretofore in the manufacture of woodscrews it has been usual toprolong the threads from the cylindrical portion of the screw to the extreme end of the point portion, thereby )lZO(lllClIlg upon the screw the well-known 2o gin let-point. In certain classes of screws as, for example, drive-serews, the entire point portion is unthreaded, the thread terminating at the base of the point, while in other forms of drive-screws the thread, which is in the form of a quick spiral, is formed on both the cylindrical and point portions.

An objection to the use of the gimlet-pointed wood-screw is that it does not readily enterintothe wood in starting unless a hole be first made for its reception, If a hammer is used for starting s'uch'a screw into wood, the thread upon the screw-point obviously acts to preventits ready entrance, as it can enter onlyby rupturing the fibers of the wood. At

' the same. time the spiral thread also acts to force the screw to one side or laterally, there- .by'renderingit somewhat difficult to enter the screw centrally into the wood.

The object of my present improvement is 40 to overcome the disadvantages just named,

and to that end I provide a wood-screw with a point portion which combines a plain or 1111- threaded centering part whichfirst enters the wood or into which material it may be inserted,

.45 and a. screw-thread which commences at the base of the plain part of the point and extends ,rearwardly in a gradually-increasing depthuntil it reaches the base of the point, where it unites with and forms a part, of the thread formed on. the cylindrical or body portion of Application filed June 28, 1889. Serial No. 315,914. (No model.)

the screw. By means-of'a point thus formed the screw may be, first entered true and centrally into the wood by a slight blow, the resistance oifered being very small, after which the screw may be driven home by a 'screw- 5 5 driver or other means, as usual.

In the appended drawings, Figure l is a perspective View of my improved wood-screw,

.the diameter across the threads exceeding the size of the wire or unthreaded portion of the shank. Fig. 2 is a similar View, the threaded and unthreaded portions of the screw-shank being of the same diameter; and Fig. 3 is a portion of a screw having asharpened poly onal point provided with athread which van- 6 5 ishes about midway of the points length.

In the drawings, a'indieates my improved wood-screw complete. I

.11 small designates the nut-breaded shank portion of the screw, andt the screw-thread, the root or core-at the base of the threads being indicated by r. The head of the screw may be provided with a head h, having a screw-driver nick n therein, as usual; or'the screw may be provided with any well-known form of head.

My invention resides in the novel construc: tion of the point portion 19 of the screw. This portion I, preferably make tapering, terminating at the end in sharpened point e. The thread i extends from the body portion 1 of the screw, pastthe base of the point portion, and terminates about midway thereof, as clearly shown bythedrawings. The thread is, as-before stated, a continuation of the main thread 2. The normal size of the thread ceases at the base :of the point portion, and

is continued therefrom toward the point at substantially the same piteh, but gradually decreasing in width'and depth until it van- 9o ishes at a point 0' into the points surface, the remainingip'art c of the point portion 1) being plain or-ul'lthreaded and terminating in the sharpened. point e, as represented in Figs. 1 and 2,

'iVithout departing from the spirit of my inven tion I may'make the point portion 1) of a screw polygonal and form a more or less connected diminishing threadt thereon, terminating at c, substantially as shown in Fig. 3. I00

My improved screw may be made by cutting away the metal, as in making, out screws or it may be produced 'by suitablyoperated swaging-dies by whatis known as the rolling process.

I claim as nay invention- 1. As a new article of manufacture, a woodscrew having the point portion thereof pro-. vided with a sharpened unthreaded part for entering the wood and centering itself therein, and having the other part of the point .port-ionprovided with a thread gradually increasing in width and depth until it forms a part of the normal thread at the base of .the point, substantially as hereinbefore described.

-2. A wood-screw having a sharpened coneshaped point portion 10, provided with a diminishing thread i and a plain or unthreaded part 0, extending from the termination of said thread to the end e of the point substantially as shown, and for the purpose hereinbefore described.

In testimony whereof I have affixed my signature in presence of two witnesses.

CHARLES D. ROGLERS.

Witnesses: I CHARLES HANNI GAN, GEO. H. REMINGTON. 

